Lego structures are fun to build. Part of the satisfaction comes from their fitting so well due to their regular patterned shapes and their snapping together so easily.
It would be quite another thing to have to build something with the very random-shaped plastic pieces in the picture above. The irregularity of each piece (certainly the fact that they would no longer snap together) would make it a difficult challenge to stack them together at all. For a dry stone waller, using these warped-shaped pieces would be closer to what it's like working with real stones.
Using these 'morphed' legos as representative of stone shapes, let's try to analyze what we can do with them.
Any attempt at wall building might better be accomplished by orienting the distorted plastic lego pieces on an angle or clustering similar shaped pieces together in less common curved patterns perhaps. Coursing along straight rows, in the typical lego fashion, might not be the way to go at all unless of course you filed them all down or melted them back to flat and boxy shapes again.
Thinking about having to build using this extreme kind of building material puts the emphasis on the fundamentals of 'what is structure'. Rather than reducing things to snap-together shapes or standard configurations, we have to force ourselves to think about how random three-dimensional objects can be arranged in order to build with them and why certain 'rules' don't always apply.